10 Inch

To learn more about HID lighting read our buyer's guide HID Lighting Buyer's Guide. Also check out our HPS Bulb Comparison Test pitting nine different HPS bulbs against each other.
Air cooled reflectors help keep your grow room cool by having an intake and exhaust port on each end for easy airflow access. Use 8 inch inline duct fans to help cool your reflector and exhaust out excess heat.